Re: [PATCH 1/1 V3] x86/AMD-Vi: Add additional check for invalid special->handle

[Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>]

On 9/13/2013 4:24 AM, Jan Beulich wrote:
>>>> On 12.09.13 at 19:00, <suravee.suthikulpanit@amd.com> wrote:
>> --- a/xen/drivers/passthrough/amd/iommu_acpi.c
>> +++ b/xen/drivers/passthrough/amd/iommu_acpi.c
>> @@ -664,19 +664,46 @@ static void __init parse_ivrs_hpet(char *str)
>>   
>>       ASSERT(*s == '[');
>>       id = simple_strtoul(s + 1, &s, 0);
>> -    if ( id != (typeof(hpet_sbdf.id))id || *s != ']' || *++s != '=' )
>> +    if ( (*s != ']') || (*++s != '=') )
> No, unless you have a very good reason.
Oh, sorry. This is my mistake.
>
>>           return;
>>   
>>       s = parse_pci(s + 1, &seg, &bus, &dev, &func);
>>       if ( !s || *s )
>>           return;
>>   
>> +    hpet_sbdf.id = id;
> In essence this is the only change not contained in the patch I sent.
> So I'd be inclined to commit this (and perhaps the one debug
> message adjustment below) under your name, and my proposed
> change as a separate one.
Ok.
>
>>       hpet_sbdf.bdf = PCI_BDF(bus, dev, func);
>>       hpet_sbdf.seg = seg;
>>       hpet_sbdf.cmdline = 1;
>>   }
>>   custom_param("ivrs_hpet[", parse_ivrs_hpet);
>>   
>> +static bool_t is_ioapic_overidden(u16 seg, u16 bdf, u8 handle)
> Missing __init annotation. And anyway, I can't really see why
> putting this in a separate function is a significant benefit. It's
> only being used in one place afaics.
Sorry, I forgot the __init.  I normally just like to keep to code that 
does a specific
thing inside it's own function for the ease of reading.  But this is 
purely coding style.
I can put it in the caller function if you prefer.
>
>> +{
>> +    bool_t ret = 0;
>> +    int apic = find_first_bit(ioapic_cmdline, ARRAY_SIZE(ioapic_sbdf));
>> +
>> +    while ( apic < ARRAY_SIZE(ioapic_sbdf) )
>> +    {
>> +        if ( ioapic_sbdf[apic].bdf == bdf &&
>> +             ioapic_sbdf[apic].seg == seg )
>> +            break;
>> +        apic = find_next_bit(ioapic_cmdline, ARRAY_SIZE(ioapic_sbdf),
>> +                             apic + 1);
>> +    }
>> +
>> +    if ( apic < ARRAY_SIZE(ioapic_sbdf) )
>> +    {
>> +        AMD_IOMMU_DEBUG("IVHD: Command line override present for IO-APIC %#x "
>> +                        "(IVRS: %#x devID %04x:%02x:%02x.%u)\n",
>> +                        apic, handle, seg, PCI_BUS(bdf),
>> +                        PCI_SLOT(bdf), PCI_FUNC(bdf));
>> +        ret = 1;
>> +    }
>> +
>> +    return ret;
>> +}
>> +
>>   static u16 __init parse_ivhd_device_special(
>>       const struct acpi_ivrs_device8c *special, u16 seg,
>>       u16 header_length, u16 block_length, struct amd_iommu *iommu)
>> @@ -698,16 +725,18 @@ static u16 __init parse_ivhd_device_special(
>>           return 0;
>>       }
>>   
>> -    AMD_IOMMU_DEBUG("IVHD Special: %04x:%02x:%02x.%u variety %#x handle %#x\n",
>> +    AMD_IOMMU_DEBUG("IVHD Special: %04x:%02x:%02x.%u variety %#x handle %#x used_id %#x\n",
>>                       seg, PCI_BUS(bdf), PCI_SLOT(bdf), PCI_FUNC(bdf),
>> -                    special->variety, special->handle);
>> +                    special->variety, special->handle, special->used_id);
>>       add_ivrs_mapping_entry(bdf, bdf, special->header.data_setting, iommu);
>>   
>>       switch ( special->variety )
>>       {
>>       case ACPI_IVHD_IOAPIC:
>> -        if ( !iommu_intremap )
>> +        if ( !iommu_intremap ||
>> +             is_ioapic_overidden(seg, bdf, special->handle) )
>>               break;
>> +
>>           /*
>>            * Some BIOSes have IOAPIC broken entries so we check for IVRS
>>            * consistency here --- whether entry's IOAPIC ID is valid and
>> @@ -725,10 +754,7 @@ static u16 __init parse_ivhd_device_special(
>>                   return 0;
>>               }
>>   
>> -            if ( test_bit(special->handle, ioapic_cmdline) )
>> -                AMD_IOMMU_DEBUG("IVHD: Command line override present for IO-APIC %#x\n",
>> -                                special->handle);
>> -            else if ( ioapic_sbdf[special->handle].pin_2_idx )
>> +            if ( ioapic_sbdf[special->handle].pin_2_idx )
> Again - no, unless you have a very good reason.
I think with the check for command line stuff already handle prior to 
this point,
I don't see why we still need to keep this here.  It should not need to 
go through
the logic here.
>
>>               {
>>                   if ( ioapic_sbdf[special->handle].bdf == bdf &&
>>                        ioapic_sbdf[special->handle].seg == seg )
>> @@ -770,6 +796,16 @@ static u16 __init parse_ivhd_device_special(
>>           }
>>           break;
>>       case ACPI_IVHD_HPET:
>> +        if ( hpet_sbdf.cmdline )
>> +        {
>> +            AMD_IOMMU_DEBUG("IVHD: Command line override present for HPET %#x "
>> +                            "(IVRS: %#x devID %04x:%02x:%02x.%u)\n",
>> +                            hpet_sbdf.id, special->handle, seg, PCI_BUS(bdf),
>> +                            PCI_SLOT(bdf), PCI_FUNC(bdf));
>> +            hpet_sbdf.iommu = iommu;
>> +            break;
>> +        }
>> +
>>           /* set device id of hpet */
>>           if ( hpet_sbdf.iommu ||
>>                (hpet_sbdf.cmdline && hpet_sbdf.id != special->handle) )
>> @@ -777,12 +813,10 @@ static u16 __init parse_ivhd_device_special(
>>               printk(XENLOG_WARNING "Only one IVHD HPET entry is supported\n");
>>               break;
>>           }
>> +
>>           hpet_sbdf.id = special->handle;
>> -        if ( !hpet_sbdf.cmdline )
>> -        {
>> -            hpet_sbdf.bdf = bdf;
>> -            hpet_sbdf.seg = seg;
>> -        }
>> +        hpet_sbdf.bdf = bdf;
>> +        hpet_sbdf.seg = seg;
> I don't see what benefit these HPET related changes provide. Or
> if there is any that I overlook, then the previous uses of
> hpet_sbdf.cmdline should all be eliminated.
>
> Jan
>
I found an issue when I was testing.  if the "handle" for the IVRS HPET 
is not the same where:
     - IVRS Table HPET handle = 0x0
     - HPET Table = 0x2

This throws the following error message:
(XEN) AMD-Vi: Failed to setup HPET MSI remapping: Wrong HPET

In this case, the handle is wrong and I am trying to change it.
When I am trying to specify the command line option "ivrs_hpet[2]=00:14.0"
this does not get used because the in the parse_ivrs_hpet() did not 
store the
override id.  So, I modify the logic in the parse_ivrs_hpet() to 
override the hpet_sbdf.bdf
with the new ID specified from command line.  Then it doesn't need to go 
though this logic here.
Also, the check "hpet_sbdf.cmdline && hpet_sbdf.id != special->handle" 
should also be eliminated.

I will send out V4 with updates, and thank you for your patience.

Suravee